Clinical symptoms, diagnosis, and treatment of neurocysticercosis

Abstract

The infection of the nervous system by the cystic larvae of Taenia solium (neurocysticercosis) is a frequent cause of seizure disorders. Neurocysticercosis is endemic or presumed to be endemic in many low-income countries. The lifecycle of the worm and the clinical manifestations of neurocysticercosis are well established, and CT and MRI have substantially improved knowledge of the disease course. Improvements in immunodiagnosis have further advanced comprehension of the pathophysiology of this disease. This knowledge has led to individualised treatment approaches that account for the involvement of parenchymal or extraparenchymal spaces, the number and form of parasites, and the extent of degeneration and associated inflammation. Clinical investigations are focused on development of effective treatments and reduction of side-effects induced by treatment, such as seizures, hydrocephalus, infarcts, and neuroinjury.

Figure 1:. Geographical prevalence of Taenia solium

Reproduced from the First WHO report on neglected tropical diseases by permission of the World Health Organization.

Figure 2:. Lifecycle of Taenia solium

Reproduced and adapted from Garcia and colleagues.

Figure 3:. Growth stages of Taenia solium

Infective T solium egg (A), larva or cysticercus (B), evaginating cysticercus (C), tapeworm scolex (D), and tapeworm strobila (E).

Figure 4:. Pathology of cysticercosis

(A) Cerebral cysticercosis in a pig brain. (B) Typical cysticercal membrane (haematoxylin and eosin stain).

Figure 5:. MRI imaging of human neurocysticercosis

Contrast used was gadoterate meglumine. Viable cysts in structural MRI (A); and enhancing nodule (B); many brain calcifications visible (C); massive parenchymal neurocysticercosis (D); basal subarachnoid neurocysticercosis (E); and intraventricular cysticercosis (F).

Figure 6:. MRI scans before and after treatment in a patient with multicystic parenchymal neurocysticercosis

The patient was a 50-year old man who received 10 days of combined albendazole (15 mg/kg per day) plus praziquantel (50 mg/kg per day) standard treatment. The follow-up MRI was taken 6 months after treatment onset. Arrows show characteristic lesions of multicystic parenchymal neurocysticercosis.